Why is the Sicilian Defense considered the best defensive opening for black

The Sicilian is known for its offensive rathe than passive defense often giving black equal or even better chances to counterattack and win, unlike some solid defenses such as the French or the Carocan which tend to draw more

Thats the best way to spell Caro Kann I have ever seen.

The sicilian may be objectively very strong, but it is only venomous in the right players hand. Most players do not have a playstyle that fit most sicilians. It is my opinion that the sicilian is probably a bit more popular than what it should be.

Black also gets to choose which mainline of the sicilian gets played, which is a major advantage below masters when you consider how much theory there is for white to know. Which pressures white to play an anti-sicilian, and those aren't difficult to deal with.

e4/e5 would be the other contender but I feel white has alot more control over the game here, and it's a very tactical variation which... favors the player with control.

Then there's the fact that the sicilian can form the basis of how black responds to the Reti and English. Which frees black up to play whatever he likes against d4.

I still believe the sicilian is the best defense in chess.

sicilian is the best opening because it is the most fun opening. but it is also rich and tactical and there are so many great options to choose from

Yes

I switched to the Sicilian as my main a year or so ago. I enjoy how complex and challenging it is - though I've lost quite severely on many occasions.

It's great for dynamism, and those looking for sharper fighting games. Keeps things interesting, for sure.

But be prepared to fall on your own sword more often than you might with some other defenses ...

i used to hate how popular the sicilian is,and i still dont play it but now i have come to appreciate why its so popular. 
Basically, if you look at blacks defenses vs 1.e4 and you want a fighting game without having to risk a higher than average eval score right of the bat, you really dont have much of a choice. Esp if you playing someone say 200 points weaker than you and its inclined to draw.
lets run the gauntlet:
1.e4 e5 is is of course one of the best responses, but in most lines, white is clearly in the driver's seat, it is called the spanish torture for a reason and white gets most of the fun in the italian. 
1.e4 e6. French would be up there with the sicilian except for one bitsy little problem, the exchange variation really dries up the position and beating weaker players from the black side of the exchange is tedious thankless work. Most people wanting to win will accept a worse eval so long as there is more to work with in the position
1.e4 c6, caro kahn is simply not a fighting opening, and the few lines that are tend to carry higher risk.
All the other sensible defenses (scandi, pirc/modern, alekhine, nimzowitsch, owens) can certainly give you a spicy game but you must be prepared to meet their critical lines , often white's advantage only sizzles out by like move 20 in these defenses. Thats the prize you pay for the excitement.
Sicilian is the ideal balance between, great eval, richness in main and sideline possibilities and no easy way for white to create a snoozefest. Thats why its so popular.
the main reason 1.d4 has become more popular over the years are the top level is that 1.e4 has suffered from the level of theory he must know to play agaisnt the sicilian well and the ease of drawing with the berlin defense. 1.d4 also has top tier asymmetrical defenses like the nimzo indian and the grunfeld but the problem is that black cant force either of those

THIS, this is a great piece of text. I've always played the caro kann and hated the Sicilian, because it was just too "overused" in my opinion. But as I've seen almost all openings otherwise are just not good enough. Caro kann? Good, but it makes you defensive more then aggresive. KID? Nope, still too defensive. Any gambits? At that point your just getting into a messy situation. But from a standpoint of openings. the undisputed best one is and always will be the sicillian

As a 1...e5 player, I love it when Black plays 1...c5.

Gives me a chance to get my creative juices flowing. My opponents often regret their opening choice.

60% wins as White against the Sicilian in my games, as opposed to 38% in the general chess.com database. I'll take those odds any time.

The Sicilian is way to theory intensive for my liking. And even at my peak as a USCF A player openings were not deciding my games. It took awhile but I finally settled on the London and white and the CK has black due to the pawn structures.

Black also has equal or better chances to *lose* with the Sicilian too. It's a double-edged sword.

Though I believe that's part of its appeal, too - the risk of it is attractive to players who want to play with fire.

The French and Caro-Kann are NOTHING ALIKE. In fact, the French is most in line with the Sicilian, and one can transpose to the other. The Caro-Kann is a far more positional defense where King Safety is the top priority. The French is a violent opening.

^^^^^^ - Read pairatrbt99chess's post only if you are really desparate to lose brain cells!